Google
Câu hỏi: Cho $\int\limits_{0}^{\dfrac{\pi }{2}}{f\left( x \right)dx}=5.$ Tích phân $\int\limits_{0}^{\dfrac{\pi }{2}}{\left[ \sin x+f\left( x \right) \right]dx}$ bằng
A. 4.
B. 8.
C. 6.
D. 7.
A. 4.
B. 8.
C. 6.
D. 7.
Ta có $\int\limits_{0}^{\dfrac{\pi }{2}}{\left[ \sin x+f\left( x \right) \right]dx}=\int\limits_{0}^{\dfrac{\pi }{2}}{\sin xdx}+\int\limits_{0}^{\dfrac{\pi }{2}}{f\left( x \right)dx}=-\cos \left| \begin{aligned}
& ^{\dfrac{\pi }{2}} \\
& _{0} \\
\end{aligned} \right.+5=6$.
& ^{\dfrac{\pi }{2}} \\
& _{0} \\
\end{aligned} \right.+5=6$.
Đáp án C.